package cn.enilu.flash.api.utils;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

public class CodeUtil {
    public static String getCode(HttpServletResponse response) throws IOException {
        String s = "QWERTYUIOPASDFGHJKLZXCVBNM1234567890";

        int charNum = 5;
        int width = 20 * charNum;
        int height = 28;

        // 1. 创建一张内存图片
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        // 2.获得绘图对象
        Graphics graphics = bufferedImage.getGraphics();

        // 3、绘制背景颜色
        graphics.setColor(Color.WHITE);
        graphics.fillRect(0, 0, width, height);

        // 4、绘制图片边框
        graphics.setColor(Color.GRAY);
        graphics.drawRect(0, 0, width - 1, height - 1);

        // 5、输出验证码内容
        graphics.setColor(Color.RED);
        graphics.setFont(new Font("宋体", Font.BOLD, 22));

        // 随机输出4个字符
        Random random = new Random();
        String verity = "";
        int x = 5;
        for (int i = 0; i < charNum; i++) {
            int index = random.nextInt(s.length());
            String content = String.valueOf(s.charAt(index));
            verity = verity+content;
            graphics.setColor(new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255)));
            graphics.drawString(content, x, 22);
            x += 20;
        }
        // 6、绘制干扰线
        graphics.setColor(Color.GRAY);
        for (int i = 0; i < 5; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int y2 = random.nextInt(height);
            graphics.drawLine(x1, y1, x2, y2);
        }

        // 释放资源
        graphics.dispose();

        // 图片输出 ImageIO
        ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
        return verity;
    }
}
